how are you drinking the water? Are you chugging it? drinking through a straw? Its possible that with your adding more water to your diet, you could be swallowing a lot more air as well, and that could be causing your bloating. It could also be a side effect of the constipation. When you're constipated you're still building up stool, that stool rests in your colon and ferments, causing gasses to get pushed back through the intestines causing that bloating. Sorry if this grosses you out, but you asked lol.
I think your digestive system just needs to right itself, which may take some time. If you don't take a probiotic, I suggest taking one. Hopefully that will help move the healing process along and the bloating will stop soon.
No, I haven't been chugging the water, so I imagine I'll probably just need to give my body time to right itself. I'll also buy some probiotic yogurts sometime.